Semiconductor transistors, in particular field-effect controlled switching devices such as a MISFET (Metal Insulator Semiconductor Field-effect Transistor), in the following also referred to as MOSFET (Metal Oxide Semiconductor Field-effect Transistor), a JFET (Junction Gate Field-effect Transistor) and a MESFET (Metal Semiconductor Field-effect Transistor) have been used for various applications including but not limited to use as switches in power supplies and power converters, as a voltage-controlled resistance, in consumer electronics, for example stereo systems, and communication technology, for example for microwave frequency communications and radar.
Particularly with regard to power devices capable of switching large currents and/or operating at higher voltages, low on-state resistance Ron, low leakage current, low switching losses and/or low parasitic device capacitances such as the Miller capacitance, which is related to the gate-drain capacitance between the gate electrode and the drain region of the field-effect transistor and the gate-source capacitance between the gate electrode and the source region of the field-effect transistor, are often required
Further, there are on-going developments to increase the yield of the manufacturing of semiconductor transistors.
For these and other reasons there is a need for the present invention.